Anesthesiology often solicits the management of emergencies, both patient and doctor induced like massive hemorrhage, increased intracranial tension, cardiac diseases and drug related errors and surgical errors. This article offers a brief prologue, followed by the management of these varied prospects of anesthesia.
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blood transfusion check

Image: “Hospital Corpsman Megan Beach, checks the flow of blood through a cell saver, during training for an antilogous blood transfusion aboard Military Sealift Command (MSC) hospital ship USNS Mercy (T-AH 19).” by U.S. Navy photo by Journalist Seaman Apprentice Mike Leporati. License: Public Domain


Patient Induced Emergencies

A massive hemorrhage is a major appalling cause of preventable mortality. The leading causes of massive hemorrhage are as follows:

  • Trauma or assault: Coagulopathy of trauma is unique in its pathogenesis being aided by tissue injury factors. It can occur in the absence of significant fluid administration, clotting factor depletion or hypothermia.
  • Vascular disease such as ruptured aneurysm: fortunately seldom, sudden loss of blood volume in such situations makes them potentially lethal.
  • Genetic bleeding disease like hemophilia
  • Postpartum hemorrhage: evidence suggests presence of an acquired fibrinogen deficiency state complicated by dilutional coagulopathy and exaggerated fibrinolysis in these patients.
  • Drug induced: as a known complication of blood thinners and anti-platelets and adverse effect of some drugs as gastrointestinal hemorrhage secondary to NSAIDs.
  • Surgical error: inadvertent damage to a major vessel is a potential cause of intra-operative blood loss.

A hemorrhage is often classified as anticipated and of unexpected character.

Major surgical interventions like cardiac, spine and vascular surgeries have an inherent risk of blood loss and give time for anticipatory preparation. However, unexpected circumstances like undetected bleeding disorder, prior to surgery, also exist.

In order to initiate the same appropriate emergent behavior in the team, various humble attempts at defining MBT have been made such as:

  • Replacement of one entire blood volume within 24 hours
  • Transfusion of >10 units of packed red blood cells (PRBCs) in 24 hours
  • Transfusion of >4 units of PRBCs in 1 hour when on-going need is foreseeable
  • Replacement of 50% of total blood volume (TBV) within 3 hours.

Massive Transfusion Protocol

symptoms of acidosis

Image: “General symptoms of acidosis.” by Häggström, Mikael. “Medical gallery of Mikael Häggström 2014”. Wikiversity Journal of Medicine 1 (2). DOI:10.15347/wjm/2014.008. ISSN 20018762. License: Public Domain

Timely detection and appropriate prophylactic management are essential. An improvement in the understanding of various tenets of hemorrhage and its management has led to the formulation of pro-active evidence based “massive transfusion protocols” as a collaborative effort of anesthesiologists, surgeons, transfusion medicine physicians, emergency physicians and intensivists.

Designed to break through the vicious lethal triad of coagulopathy, acidosis and hypothermia, MTP calls for aggressive rapid judicious empirical use of blood and blood derivatives for the management of a massive hemorrhage to ensure an improved outcome.

Once MTP is initiated, a batch of 5 red blood cells, 5 platelets and 2 fresh frozen plasma (FFP) are to be dispatched. Further batches of blood and blood products are dispatched until needed.

The pre-requisites for successful MTP are:

  • Intravenous access: Large bore peripheral intravenous access is at the heart of any successful resuscitation. Special insertion sheaths in neck veins may be used, subject to the accessibility and expertise of the team.
  • Temperature control: warming devices, surface warmers and core temperature monitors. With transfusion of 2 or more blood products, it is of crucial significance to gradually warm these blood products “thawing“ them to body temperature prior to transfusion to prevent complications secondary to massive infusion of stored blood products like “Disseminated Intravascular Coagulation (DIC)
  • Central venous pressure monitoring.

Onsite testing such as arterial blood gas and thromboelastography is highly desirable.

Increasing use of blood thinners, especially in the elderly subset, has witnessed a rise in transient coagulopathy-like states during surgeries due to drug use.

Ideally, warfarin and similar vitamin K antagonists should be stopped about 5-7 days prior to surgical intervention with an overlap of heparin. PT/INR should be monitored and heparin is to be stopped a day prior as per the drug specifications.

In case of emergency, prothrombin plasma concentrates (PCC) are to be used to reverse warfarin effects.

Heparin antidote is protamine sulfate. Newer fractionated low molecular weight heparin formulations are difficult to reverse.

In case of antiplatelet agents like aspirin and clopidogrel, they are to be withheld with the consent of the treating physician supervision and appropriately replaced with heparin if possible.

Low dose aspirin leads to minimal, if any, increase in bleeding tendency.

Alternative strategies:

tranexamic acid structural formula

Image: “Structural Formula of Tranexamic Acid.” by Jü – Own Work. License: Public Domain

  • Activated factor VII: benefit in uncontrolled bleeding unresponsive to standard hemostatic therapy is equivocal.
  • Antifibrinolytic agents: early administration of drugs such as tranexamic acid has a mortality benefit in trauma and obstetric hemorrhages.
  • Cell salvage: of use in patients with rare blood groups and unexpected massive hemorrhages and feasible in aseptic environments such as operating suites, cell savage carries potential risk of malignant cells dissemination and contamination.

Complications of MTP:

Massive transfusion is not without complications. Overzealous rapid correction without due central venous pressure monitoring can potentially lead to circulatory overload, interstitial edema and pulmonary edema. These catastrophic complications can be life threatening.

There are no loud tell-tale signs of pulmonary edema, but for a subtle drop in oxygen saturation. Aggressive diuretic use with curtailed intravenous fluid administration is necessary. Other complications can be compiled as follows:

Immediate complication Intermediate complication Long term complication
Acidosis TRALI (transfusion related acute lung injury) Renal failure
Hypomagnesemia Cardiac toxicity secondary to hypocalcemia, hyperkalemia and other factors. Respiratory failure
Hyperkalemia Disseminated intravascular coagulation (consumptive coagulopathy) SIRS (systemic inflammatory response syndrome)
Citrate toxicity Interstitial edema Thrombotic complications
Hypothermia Transfusion related circulatory overload Sepsis
Hypocalcemia Pulmonary edema
Dilutional coagulopathy

Limitations of Massive Transfusion Protocols

  1. Inappropriate initiation of MTP leads to a waste of energy and resources.
  2. It is not standardized, and the protocol varies largely from institution to institution.
  3. Increased intracranial pressure:
    Protective though, the skull is a rigid, non-compressible limiting element for the intracranial contents. The intracranial space of about 1700 ml is distributed as follows: Brain parenchyma about 1400 ml, blood 150 ml and CSF about 150 ml. The brain parenchyma, blood, minimal interstitial fluid with CSF is all in a balanced flexible dynamic equilibrium state. If any of them increases, the others compensate. This principle has been formally addressed as the Monro-Kellie doctrine. However, decompensation of this intimate balance leading to raised intracranial pressure as in presence of SOL (space occupying lesion as tumors), hydrocephalus (increase in CSF component) and extra-axial blood aggregation as in trauma and brain hemorrhage has abysmal effects on cerebral perfusion leading to ischemia and parenchymal damage.

Cerebral blood flow autoregulation, in normal circumstances, ensures adequate cerebral perfusion over a wide range of intracranial pressure. Autoregulation is often impaired in the presence of intracranial SOL, trauma and infection.

Clinical reflection of raised intracranial pressure is the Cushing’s triad: hypertension, bradycardia and irregular respiration. Cushing’s triad is the brain’s last ditch stand effort to maintain cerebral perfusion in face of increasing cerebral edema.

Increased intracranial pressure in these circumstances can potentially lead to the nearly always fatal complication; “coning”, the herniation of posterior fossa contents, brain stem and cerebellar tonsils through the foramen magnum leading to compression of the critical medullary cardiovascular regulatory centers.

Raised intracranial pressure calls for rapid emergent co-ordinated management.

Intubation: The first traditional step in resuscitation is to control the airway and avoid hypoxia. However, subtle stimulation of the vocal cords can lead to a raised intracranial pressure, tachycardia and hypertension.

Anesthesia drugs have varied effects on intracranial pressure. In the face of impaired autoregulation and deranged systemic parameters, normally perfectly safe anesthetic agents, like analgesics and sedatives, can also lead to major changes in intracranial pressure, cerebral blood flow and cerebral metabolism. Inappropriate naïve use of these drugs can cause patient deterioration.

Decongestant drugs, which ameliorate intracranial pressure, are prone to reducing cerebral blood flow below critical levels with resultant cerebral hypoperfusion and elevated risk of ischemic hypoxic encephalopathy and brain damage.

Hence, a judicious use of these agents to achieve a perfect balance between intracranial pressure and cerebral perfusion is a must.

Various drugs with their effects are summarized below for easy memorization:

Drug Effect
Hypnotic agents: propofol Reduction of cerebral blood flow, decrease in cerebral metabolism, decrease ICP, decrease in cerebral perfusion pressure
Benzodiazepines: lorazepam, diazepam Reduction of cerebral blood flow, decrease in cerebral metabolism, decrease ICP, decrease in cerebral perfusion pressure
Opioids: fentanyl, sufentanil Reduction of cerebral blood flow, decrease in cerebral metabolism, no change in ICP; increase in blood volume can lead to secondary increase in ICP.
Alpha-2 adrenergic agonists: clonidine Reduction of cerebral blood flow, no change in cerebral metabolism, no change in ICP; occasional transient decrease in ICP with low dose
Ketamine Region specific variable response of blood flow, variable response of cerebral metabolism, increases ICP
Diuretics: furosemide, mannitol Reduce ICP, reduce cerebral blood flow, decrease cerebral perfusion pressure

Cardiac Diseases

Cardiovascular diseases are the leading cause of mortality. Cardiac disease like ischemic heart disease, arrhythmias and severe vascular diseases like aortic stenosis, can lead to heart failure and eventually cardiac arrest.

Cardiac arrest can also be the culmination of pulmonary embolism, tension pneumothorax, cardiac tamponade or hypovolemic shock.

The Advance Cardiac Life Support (ACLS) guidelines published in 2015 and valid through to 2020, determine emergent cardiac management. As per the protocol, the surgeon is responsible for CPR (cardio-pulmonary resuscitation) and the anesthesiologist for managing the drug administration and patient monitoring. The latter is inclusive of ECG interpretation, monitoring oxygen saturation, end-tidal carbon dioxide and checking for signs of airway obstruction and respiratory issues.

Ventricular arrhythmias like pulseless ventricular tachycardia and ventricular fibrillation call for the use of defibrillation.

Atrial arrhythmias are common, usually benign and often managed without taking recourse to the management of cardiac arrest.

Some salient features of ACLS pertinent to anesthesiology are as follows:

  • Low end tidal CO2 (ETCO2 < 10mm Hg) after 20 minutes of CPR in conjunction with other parameters helps determine when to terminate resuscitation.
  • Extracorporeal CPR can prolong viability if rapidly implemented.
  • Avoidance of immediate correction of hypotension is recommended during post-cardiac arrest care.
  • In absence of hypoxia or respiratory distress, oxygen administration is rather to be withheld in patients with acute coronary syndrome.
  • Patients in cardiac arrest with no definite pulse are to be given focused high quality CPR with naloxone.

Doctor Induced Emergencies

Wrong Drug and Wrong Dose Errors

Medication error is defined as “treatment process fallacy that potentially culminates in harm to the patient”. Drug errors are the commonest misadventures suffered by patients in hospitals. There are different tiers of medication errors:

  • Prescribing faults: over and under-prescribing
  • Prescription errors: fault in writing prescriptions, illegibility, wrong drugs
  • Manufacturing errors: adulterants
  • Dispensing errors: wrong drug, wrong formulation
  • Administering errors: wrong dosage, wrong access and wrong frequency.

It’s unfortunate but true that medication errors are rather common in anesthesia. Almost no one is spared. Most of them are, however, trivial and seldom serious. Timely recognition helps in the correction of any untoward hemodynamic change that would have occurred and evade an adverse event. If otherwise, there is potential risk of patient harm.

Measures to prevent these mortal errors causing patient morbidity are:

  • All syringes to be labeled with drug name and concentration
  • No syringe to be used in more than one patient
  • Careful monitoring of the use of controlled drugs
  • Computerized physician order entry system: These computer generated programs have inbuilt warnings about possible drug interactions, duplication of orders, wrong dose ordered and patient allergies to given medication. They epitomize objective control over human errors to some extent.
  • The best way to avoid wrong dose, wrong drug issues is constant vigilance. Careful prescription, administration and expert observation after administration can help avert potential complications.

Surgical Errors

Surgical care is an indispensable part of medical armamentarium since times immemorial. As grave as they could be, surgical errors too have lingered in literature for a long time. They represent constant concern of surgeons and health care organizations.

Common errors include:

  • Wrong side surgery
  • Inadvertent opening of cavities as opening of gut leading to contamination and peritonitis
  • Vessel damage leading to hemorrhage.

While addressing the safety of surgical care, WHO, in 2007, took up the challenge of reinforcing “Safe Surgery Saves Lives”.

At the heart of this, the WHO initiative is the WHO Safe Surgery Checklist. Three phases of operation are addressed in this check list:

  • Before induction of anesthesia “Sign in”
  • Before incision of the skin “Time out”
  • Before the patient leaves the operating room “Sign out”.

In each phase, a check list co-ordinator checks various points to ensure complete surgical safety. A few salient points are as follows:

  • Confirm patient identity
  • Confirm the side of surgery whenever applicable; to mark the same
  • Complete instrument count, mop count
  • All anticipated complications are to be listed beforehand to avoid unpleasant surprises intra-operatively.

The aim is to follow a few critical steps rationally to avoid these infrequent, but persistent, mishaps endangering the well-being of surgical patients.

Summary

Patient induced emergencies include massive hemorrhage, increased intracranial pressure and cardiac diseases.

Doctor induced emergencies comprise of wrong drug and wrong dose administration and surgical errors.

A massive hemorrhage demands objective massive transfusion protocol based rapid judicious management in order to successfully revive the patient avoiding inherent risks of the protocol.

Anesthetic drugs have to be used wisely in situations with increased intracranial pressure to ensure adequate cerebral perfusion with decreased intracranial tension.

Cardiac diseases constitute common emergencies and have to be managed as per the ACLS guidelines.

Doctor induced errors are common, but mostly trivial and inconsequential if managed at the right time. Expert emergent, conscious, careful management to avoid patient harm should be the goal.

Review Questions on Patient and Doctor Induced Emergencies

The correct answers can be found below the references.

1. What does not represent a patient induced emergency?

  1. Wrong drug administration
  2. Aneurysm rupture
  3. Myocardial infarction
  4. Trauma

2. With respect to oxygen administration as per the latest ACLS guidelines, which, of the following statements, is correct?

  1. High flow oxygen to be given to all suspected patients
  2. High flow oxygen not to be given to all suspected patients
  3. In the absence of respiratory distress, no supplementary oxygen to be given
  4. Oxygen to be given only if the patient is unconscious.

3. Towards limitation of which errors has WHO constituted a check list?

  1. Drug dosage error
  2. Surgical error
  3. Cardiac disease management
  4. Chest trauma management

 

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